The former protégé of gospel great Mahalia Jackson, Walker was often called the Queen of Gospel. At the age of 22, Walker formed the gospel group the Caravans, which released such hits as "Mary Don't You Weep," "No Coward Soldier," "Tell the Angels" and "Sweeping Through the City."

Walker's singing once stopped the filming a movie, because the actors were so moved by the gospel legend's voice.

Still, the Chicago native told the Los Angeles Times that more important than her voice, was the message her songs carried.

"What's from the heart reaches the heart," she said. "And if you've got a heart and you listen to what we're doing, you're going feel something - white, black, yellow, green, red, it don't make no difference, you're going to feel something."

Walker often performed at the White House and even received special recognition by former President George W. Bush.

In a written statement released by the White House on Sunday, President Obama said he was saddened over Walker's passing.

"Ms. Walker's voice and message has touched congregations across the nation," the statement read. "Though we have lost an American icon, her influence on gospel music will continue for generations. Our thoughts and prayers are with her family and the countless lives she touched."

Walker's funeral will be held at 11 a.m. Friday, Oct. 15 at the West Point Baptist Church in Chicago.